Interest in well-being has increased. This involves personal well-being as well as health care. This has resulted in many personal and medical monitoring devices, such as sensors. Such sensors can be embedded in clothing, such as gloves, mitts, footwear, helmets, etc. As for force or pressure sensors for garments, they may be e.g. piezo resistive, piezoelectric, or capacitive. Touch sensors, i.e. tactile sensors, are most often capacitive. A capacitive force/pressure/touch sensor typically involves only easily available materials. As an example, the patent FI 127245 discloses a capacitive force and/or pressure sensor. As opposed to a force and/or pressure sensor, a touch sensor needs not to have deformable material near an electrode.
Referring to FIG. 1, such sensors typically comprise a microelectronic chip 910, which is a rigid component. The microelectronic chip 910 comprises input/output channels 912a, 912b, such as bumps. These input/output channels 912a, 912b are located close to each other in order to have many input/output channels 912a, 912b for the chip 910 for better functionality.
Particularly in wearable sensors, the comfort of use is preferred. Therefore, a large part of the sensor may be formed on conformable sheet 930. The conformable sheet 930 may include wiring 932 that is also conformable and electrically conductive. Such wiring 932 may be made e.g. by printing. However, because of manufacturing techniques, the line width of the conformable wiring 932 is typically much larger than required by the distances between the input/output channels 912a, 912b of the microelectronic chip 910.
In order to electrically join the conformable wiring 932 to the input/output channels 912a, 912b, a flexible circuit board 920 may be used in between the microelectronic chip 910 and the conformable sheet 930. A flexible circuit board 920 can be manufactured with much smaller line width that a conformable wiring 932. Thus, the wiring 922 on the flexible circuit board can be made, at a first location, sufficiently narrow so as to contact the input/output channels 912a, 912b; and at a second location, the wires of the wiring 922 can be separated from each other so as to contact the wires of the conformable wiring 932.
However, such a solution is often mechanically unreliable. In particular, when used in such a way that the shape of the conformable part 930 and/or flexible part 920 changes, reliability problems are often encountered.